Ceramic in replacement components

ABSTRACT

A method and apparatus for a prosthesis. At least a portion of the prosthesis is made from a ceramic that is treated with ion implantation, which causes a controllable, bilateral compressive stress of the ceramic. A diamond-like-coating (DLC) can be coated on the ceramic and in the same chamber as the ion implantation. After treating by ion implantation and coating with DLC, the ceramic will be strengthened and have a low coefficient of friction and thereby be made much less likely to fracture under load.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to ceramics. More specifically,a method of improvement of ceramics in replacement components, such ascomponents in hip and knee replacements.

2. Description of the Related Art

It's inevitable that all living things age overtime, so do the manycomponents that make up the living things. Human beings are also livingthings and we have the ability to regenerate some of our components whenthey wear out or some of the components are just naturally replaced. Forexample, our skin cells are continuously replaced on a daily basis, haircells are continuously added so that hair can grow, and calcium iscontinuously absorbed and reabsorbed in bone components. The absorptionof calcium in the bones helps to strengthen them. However, because ofaging, degenerative diseases, such as osteoporosis, or other causes, thebones can become fragile and break causing excruciating pain. In othercases, as in osteoarthritis, the cartilage becomes worn away and bonedeformities develop. The load-bearing situation on bone-on-bone is verypainful. In addition, primarily in younger patients, sports-relatedinjuries can lead to severe damage to hips or knees, necessitatingsurgery.

For many years, man-made devices have been developed in order to helpreplace components that cannot be regenerated and are no longerfunctioning properly. Such man-made devices include biocompatibledevices and materials. The devices include heart valves, pace makers,spinal, dental, or breast implants, collagen for soft tissueaugmentation, and orthopedic devices, such as total knee and hip jointreplacements.

Artificial joints can include a plastic-cup made of ultrahigh molecularweight polyethylene (UHMWPE) that is placed in a joint socket, a metal(titanium alloy or cobalt chromium alloy) or ceramic (aluminum oxide orzirconium oxide) ball that is complementary to the cup and is affixed toa metal stem. These artificial joints are used to replace hip, knee,shoulder, and other joints in order to restore function afterdegeneration, car and construction accidents, and sport injuries.

However, these artificial joints typically do not last, as long asneeded, especially when the patient is young and can typically livelonger due to medical advancements. Conventional artificial joints lastabout 10 years and need to be replaced due to wear and loosening.Additionally, due to localized stress from the interaction of the balland socket, small particles can break off from the surface andcontaminate the surrounding synovial fluid. The body's immune systemwill attempt to degrade the particles by secreting enzymes, which cankill the adjacent bone cells or cause osteolysis and lead to mechanicalloosening and failure of the artificial joints. Further, despite thebest efforts and techniques (including polishing), the surfaces of theballs can have protuberances, which through use can cause scratches thatlead to microcracks in the balls and ultimately to catastrophic fractureof the ball and joint. These fractures can be extremely painful to thepatients and require expensive replacements and surgery. The moreexpensive ceramic joint replacements are normally fitted in younger,more active patients, in the expectation that the life of the jointreplacement will be longer than that of metallic components. This hastoo often not been the case, principally due to fracture of the morebrittle ceramic.

Therefore, there is a need for a method and means to decrease particlesin the synovial fluids caused by friction on the ceramics. There is alsoa need to prevent microcracks from starting or prevent the microcracksfrom increasing in size, thereby increasing the life of the ceramicprosthesis.

SUMMARY OF THE INVENTION

The present invention generally provides for a method and apparatus tostrengthen the ceramic portion of a prosthesis. In one embodiment, amethod of strengthening a prosthesis is provided and can includetreating at least a ceramic portion of the prosthesis with a first ionbeam implantation, and coating at least the ceramic portion with adiamond-like-coating. The treating and the coating can be accomplishedin the same vacuum chamber. Treating at least the ceramic portion of theprosthesis with ion implantation can cause a controlled compressivestress in the ceramic. The at least ceramic portion can be treated byion implantation with ions in a vacuum at a dose and energy sufficientto cause the controllable compressive stress and not cause the at leastceramic portion to become amorphous. Coating can further includeexposing the at least ceramic portion of the prosthesis to a vacuum,condensing a diamond-like-carbon precursor, and bombarding with thediamond-like-carbon precursors with a second ion beam. The energy of thefirst ion beam used in the treating may be between 30-130 keV or between50-100 keV. The energy of the second ion beam used in the coating may bebetween 5-100 keV or between 10-30 keV.

In another embodiment, a method of hardening a prosthesis can includetreating a ceramic portion of the prosthesis with an ion beamimplantation with ions in a vacuum at a dose and energy sufficient tocause the controllable compressive stress and not cause the ceramic tobecome amorphous. The ceramic can be treated with 30-130 keV or with50-100 keV of energy from the ion beam. The ceramic can also be treatedwith ions having a dose of about 10¹⁷ ions per cm² or less and the ionmay be helium. The ceramic can be selected from Alumina (Al₂O₃),Zirconia, Chromium Oxide, Cr₂O₃, Silicon Oxide (SiO₂), other ceramics,or metals coated with one of the said ceramics and a combination thereofor metals coated with one of the said ceramics.

In still another embodiment, a prosthesis is provided and can include aceramic treated with ion implantation that can cause a controllablecompressive stress, and a diamond-like-coating on the ceramic, saiddiamond-like-coating can have a low friction coefficient. The ceramicmay be on a ball portion of the prosthesis or a cup portion of theprosthesis. The ceramic can be positioned in locations such as joints,knees, fingers, toes, shoulders, arms, elbows, hips, ankles, necks,spinal cord, other a combination thereof. The controllable compressivestress may be a maximum bilateral compressive stress. The ceramic can betreated and coated in the same vacuum chamber. The ceramic can betreated with 30-300 keV or with 50-100 keV of energy from the ion beam.Additionally, the ceramic can be coated with 5-100 keV or with 10-30 keVof energy from the ion beam. The ceramic can also be treated by ionimplantation with ions in a vacuum at a dose and energy sufficient tocause the controllable compressive stress and not cause the ceramic tobecome amorphous. The ceramic can be Alumina (Al₂O₃), Zirconia, ChromiumOxide, Cr₂O₃, Silicon Oxide (SiO₂), other ceramics, and a combinationthereof. The ceramic can be treated with ions having a dose of about1×10¹⁷ ions per cm² or less and the ion may be helium. The ion can alsobe selected from positive ions, nitrogen ions, calcium ions, hydrogenions, helium ions, boron ions, other ions, and a combination thereof.

In still another embodiment, the prosthesis apparatus can include aprosthesis having at least a portion made from ceramic treated by ionimplantation with ions in a vacuum at a dose and energy sufficient tocause a controllable compressive stress and not cause the ceramic tobecome amorphous. The ceramic is on a ball portion and/or a cup portionof the prosthesis. The ceramic can be positioned at joints, knees,fingers, toes, shoulders, arms, elbows, hips, ankles, necks, spinalcord, other a combination thereof. The ceramic can be treated with30-300 keV or 50-100 keV of energy from the ion beam. The prosthesisapparatus can further include a diamond-like-coating on the ceramicportion of the prosthesis.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited embodiments of the presentinvention are attained and can be understood in detail, a moreparticular description of the invention, briefly summarized above, maybe had by reference to the embodiments thereof which are illustrated inthe appended drawings.

It is to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1 illustrates an artificial hip and joint system.

FIG. 2 is an illustration of an ion implantation system.

FIG. 3A illustrates an enlarged view of microcracks that can occur inceramic balls.

FIG. 3B illustrates the microcracks after ion implantation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The embodiments of the present invention relates to a method andapparatus to increase the life of the artificial joints, such as hip,shoulder, fingers, toes, arms, elbows, ankles,-necks, spinal cord, kneereplacements and other joint replacements. The application of thepresent invention is not limited to humans, rather it can be used indogs, cats, monkeys, elephants, and other animals. The application canbe used in load-bearing or non-load-bearing surfaces or prosthesis,which may be manufactured wholly or partially from ceramic materials.

FIG. 1 illustrates an artificial hip and joint system 10. The system 10can include a hemispherical socket 12 or an acetabular cup, a sphericalball 14 that can be attached to a femoral head 16 and a femoral stem 18.The socket 12 is typically made from a metal and is lined with UHMWPE orother materials. The lining is designed to decrease the friction betweenthe socket 12 and the ball 14.

The ball 14, which is adapted to fit into the socket 12, can be madefrom ceramics. Some possible ceramics can include Alumina (Al₂O₃),Zirconia, Chromium Oxide, Cr₂O₃, Silicon Oxide (SiO₂), and others thatcan be adapted for use in vivo. The ball 14 can be constructed andarranged to mate with the femoral head 16, which is part of the femoralstem 18. The femoral stem 18 can be implanted into existing long bonethat may still be functional or can be used as the long bone, if none isavailable.

Although the liner is designed to reduce friction between the socket 12and the ball 14, over time, the liner and the ceramic can wear away dueto the reciprocating motion causing minute particles to be introduced inthe body and causing osteolysis. Additionally, the ceramic, even afterextensive polishing to remove any surface protuberances, may still havesmall amounts of protuberances therein. Additionally, the ceramic mayinherently contain microcracks or microfractures (see FIG. 3A) orfriction acting on the protuberances can cause microcracks in the ball14, both of which can lead to catastrophic failure of the ball byfracture.

In one embodiment of the invention, an ion implantation process can beused to decrease the amount of microcracks produced by friction, to stopfurther migration of microcracks and to close at least a portion of themicrocracks. At the right conditions, ion beam implantation will inducea controlled bilateral compressive stress on the ceramics, therebystrengthening it.

Ion implantation is a process that can modify near surface regions of awork piece, such as ceramic balls, without increasing the dimensions,changing the finish or causing thermal distortion. Ion implantation usesenergy beams of ions, such as low energy, high energy, direct-beam, andplasma immersion ion implantation.

FIG. 2 is an illustration of an ion implantation system 20. The system20 includes a chamber 21 that contains an ion source 22, an analyzingmagnet 23, an acceleration tube 24, a focus device 25, a neutral beamtrap and beam gate 26, a second beam trap and gate plate 27, and a workpiece holder 28. The chamber 21 is maintained at low pressure or avacuum around 1×10⁻³ to about 1×10⁻⁷ Torr. The ion source can be a gasor a solid source. The ions used herein are positive ions, such asnitrogen ions, calcium ions, hydrogen ions, boron ions, other ions andpreferably helium ions. Negatively charged electrons traveling from afilament to an anode collide within the ion source to create positivelycharged ions used in ion implantation.

The analyzing magnet 23 creates a magnetic field, where the positivelycharged ions are bent into an arc with a certain radius. The parametersof the ions that the magnet 23 analyzes are mass, speed, and charge inorder to select the desired ions. The magnet 23 allows only the desiredspecies with the specific parameters to exit from an opening providedtherein. The acceleration tube 24 accelerates the ions exiting from themagnet 23 to the desired velocity in order to penetrate the work piece.The focus device 25 uses magnetic lenses to focus the beam exiting fromthe tube 24 into a smaller beam for better implantation. The traps andgates 26 and 27 remove any neutral ions that may be present in the beamby directing the positive ions in another direction and away from theneutral ions. The traps and gates 26 and 27 can direct the positive ionstowards the work piece holder 28, which can hold the work piece, such asa prosthesis piece or the ball 14. The work piece holder 28 can includea jig capable of holding a multiplicity of ceramic components anddesigned to allow the angle of incidence of the ion beam on thecomponents to be varied, continuously or discontinuously, during ionimplantation.

In operation, the desired prosthetic portion or the ball 14 portion ofthe hip and joint system 10 can be placed in the chamber 21 for ionimplantation. The ball 14 is held in position by the work piece holder28. Helium is the preferred ion in the ion implantation process. Heliumcan be used in the ion implantation process because of its lowermolecular weight, and because it can be easily used with conventionalindustrial ion implantation system 20, with energies around 30 keV-500keV. Other ions, such as argon or nitrogen, can also be used but canrequire a Cockcroft-type ion accelerator (high-end research accelerator)to provide the necessary energies for the desired penetration. Becausehelium produces displacements towards the end of the ion range withinthe ceramic, in order to achieve a more uniform compressive stressdistribution, it is necessary to vary the ion energy, continuously ordiscontinuously, during irradiation by about a factor of four (e.g. from25 keV to 100 keV).

Once the ball 14 is held in position, the ceramic is strengthened by ionimplantation. Preferably, the energy level can be around 30-300 keV, andmore preferably around 50-100 keV, with about 1×10¹⁷ ions per cm² orless. Beyond 1×10¹⁷ ions per cm², the ceramic may become amorphous. Ifthe ceramic becomes amorphous, then the desired maximum compressivestress state is not achievable. As the helium travels into the ceramic,it causes radiation damage (recombination of vacancies andinterstitials) and displaces the targeted atoms from their latticepositions due to the volume expansion. The displacement of the targetedatoms can produce a large amount of controllable compressive stress onthe ceramic, which makes the ceramic stronger. Helium has the propertyin solid materials of being highly insoluble, and of stabilizingclusters of atomic vacancies around the helium atom. In this way, it iscapable of reducing the recombination of the said vacancies withinterstitials, produced in equal numbers during ion irradiation.

The stress is controllable because the ion implantation parameters canbe changed (increase or decrease energy levels, type of ions, such asheavyweight or lightweight, etc.), so that the compressive stress is atany compression stress state that is desired. The desired state can bedependent on the amount of stress that would be anticipated in theprosthesis. For example, in a ball for a hip replacement, where thestress is great, more compressive stress is needed, while in a ball thatmay be in a finger joint, less compressive stress is needed. Because theceramic is stronger, the microcracks that can be caused through frictionis prevented. Additionally, the ion beam should at least penetrate, asfar as, the depth of the microcracks to be the most effective.

FIG. 3A illustrates an enlarged view of microcracks that can occur inceramic balls. A ball 30 a is illustrated having microcracks 32 a and 34a. The microcracks 32 a and 34 a are typical microcracks that can occurat the surface of the ceramic ball. Even after high speed polishing, themicrocracks 32 a and 34 a can still be present. Microcrack 34 a has alarge tail portion 36 a, which if left untreated, can produce acatastrophic failure of the ceramic ball under load conditions. With theuse of ion implantation, the microcracks 32 a and 34 a can decrease insize or be prevented from further propagation.

FIG. 3B illustrates the microcracks after ion implantation. The ball 30b has microcracks 32 b and 34 b on its surface that corresponds tomicrocracks 32 a and 34 a in FIG. 3A. The ion implantation can decreasethe size of the microcracks or close up to the microcracks due to thedisplacement of the target atoms by the helium being implanted. As shownin FIG. 3A, the microcrack 32 b has been substantially closed-up. Due tothe ion implantation on the ball 30 b, microcrack 34 b and its tail 36 bhave been prevented from expanding or traveling further. The maximumcompressive stress induced in the surface region of the ceramiccounteracts the applied tensile stress due to loading and to frictionbetween load-bearing surfaces and prevents the ceramic atoms frommoving, thus, the ceramic microcracks are prevented from increasing orspreading. Because the microcracks 32 b, 34 b and 36 b are preventedfrom expanding or traveling, this will reduce the likelihood of acatastrophic failure of the ball 30 b.

It should be noted that the preferred parameters of the energy level,the amount per cm² of the ion beam should be appropriate for theparticular ion used to penetrate to the desired depth and should not beso high that the ceramic becomes amorphous. As stated above, other ionscan be used, such as nitrogen (does not stabilize vacancy-type defects,as well as helium), neon and argon (which have limited penetratingpower) and hydrogen (which has a low efficiency for producing radiationdamage in ceramic materials).

Although it is preferable, it is not required that the ion beam beutilized on all parts of the ceramic. In order to save time, materials,and costs, all the surfaces of the ceramic ball or the desired ceramicprosthesis do not have to be treated. The ceramic can be treated in theareas that are affected by friction, load-bearing surfaces or where themicrocracks occur.

By using the ion beam implantation, the ceramics that are used inprosthesis can be strengthened by increasing the compressive stress.Microcracks that are present in the ceramic of the prosthesis can beprevented from spreading, can be reduced in size, and microcracksassociated with surface flaws, such as from protuberances, can bereduced or prevented. Ion beam implantation can provide an easy,cost-effective method to strengthen ceramics for use in prosthesis.Additionally, the ion beam also “cleans” the treated surface of theceramic by sputtering so that no additional cleaning is required, shouldthe ceramic undergo additional processing, such as coating.

One such additional process in another embodiment of the presentinvention can be applying a diamond-like carbon (“DLC”) coating to theceramics to reduce the friction between the prosthesis, such as the balland cup. DLC provides a low friction, high hardness, and chemicallyinert (biocompatible) coating to ceramics. DLC is an amorphous solidcomprising a highly cross-linked carbon network with a high degree ofsp³ bonding that provides similar characteristics of diamonds. DLC maybe deposited by a variety of techniques centered on energetic ionbombardment, such as plasma assisted chemical vapor deposition (CVD),ion beam assisted sputtering, radio frequency (RF) plasma-assisted CVD,cathodic arc and laser ablation of carbon targets.

DLC depositing typically is a three-step process. In step one, thesurface of the work piece, such as a metal ball, that is to be coatedwith DLC, is cleaned with argon ions in a vacuum to remove anycontaminants. In step two, the metal ball is heated so that a bondingmaterial, such as silicon or titanium, is deposited by ion assisted beamto the metal ball to form a metal-silicon bond. In step three, an ionbeam assisted deposition of DLC is used to form a silicon-DLC bond.These steps are applied to metal prosthesis. However, DLC can be coatedon ceramics without the binding material.

In one embodiment of the invention, a ceramic prosthesis that waspreviously treated by ion-implantation (as discussed above) is coatedwith DLC. Ceramic coated with DLC provides a lower coefficient offriction (<0.1) when interacting with UHMWPE, as compared to metal whencoated with DLC interacting with UHMWPE (0.14), and is favoredespecially in the ball portion. Steps one and two can be eliminated ifthe surface has been previously cleaned by the above-mentioned ionimplantation process and the DLC is applied directly on the ceramicprosthesis, without the need of the bonding material. The DLC can bedeposited on the ceramic prosthesis in the same vacuum chamber that waspreviously used for ion implantation, without the need of anotherseparate chamber for depositing DLC.

A DLC precursor is deposited on the previously ion implanted ceramicprosthesis with the assistance of ion beam implantation. The ceramicprosthesis is cooled down below 100° C. to allow the DLC precursor tocondense onto the ceramic. In a preferred embodiment, the DLC precursoris polyphenyl ether or penta-phenyl-trimethyl siloxane, however, othersuitable precursor materials include carbon-based diffusion pumpmaterials, which have a low vapor pressure and can be vaporized stablyat room temperature. Preferable diffusion pump fluids can includepolydimethyl siloxane and elcosyl napthalene.

The precursor is vaporized and condensed onto the surface of the ceramicprosthesis using known methods. The precursor is vaporized by beingplaced in a heated reservoir and heated to about 140° C.-180° C. and thevapors are directed onto the cooled component. Simultaneously, theceramic should be bombarded, either in a continuous or interruptedfashion, with an energetic beam of ions. The preferred ion source isnitrogen, but other ions can include argon, hydrogen, silicon, methane,helium and neon. The ion beam should be between about 5 keV to 100 keV,preferably between about 10-30 keV. The ion beam bombardment helps torupture about 80% of the carbon-hydrogen bonds in the precursor, inorder to form a non-crystalline coating of amorphous carbon. The ionbeam strongly enhances adhesion of the DLC coating by rupturing andsubsequently reforming inter-atomic bonds across the interfaces. Thepreferred thickness of the DLC should between about 100 nm-1 micron.

The DLC provides the ceramic with a coating having a low coefficient offriction so that damage from tensile stresses caused by friction isminimized. DLC also provides a strong coating that increases wearresistance and increases the life of the prosthesis. The coating helpsto decrease surface microcracks that can be caused by friction. DLC ischeaper to use than actual polycrystalline diamond components becauseit's synthetic, but still provides similar characteristics as thediamond. By ion implanting to increase compressive stress and depositingDLC in the same chamber, throughput of the ceramic prosthesis isincreased. Additionally, the production time and costs are decreased dueto the elimination of at least two steps in the deposition of DLC.

The embodiments of the invention provide for a method to control thecompressive stress present in the ceramic. Once the desired compressivestress is achieved in the ceramic, then the ceramic's strength can be atits maximum capacity. After ion implantation, DLC coating can be appliedto the ceramic. With the ion implantation and the DLC coating, theceramic will be resistant to microcracks and scratches and thus, willhave a longer useful life. By having a longer useful life, the ceramicprosthesis will not have to be replaced as often as conventionalprosthesis. It will be recognized by a person skilled in the art thatthe implantation and/or the DLC coating can be applied to allload-bearing surfaces used in the prosthesis, including the ball andsocket.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

1. A prosthesis, comprising: a prosthetic joint comprising a ball portion and a cup portion said ball portion having an outer load bearing surface configured to engage with a load bearing surface within said cup portion; a ceramic treated with ion implantation, wherein said ion implanted ceramic is characterized as having a compressive stress in said surface due to said ion implantation wherein said ion-implanted ceramic with said compressive stress is not amorphous, wherein said ion implanted ceramic is said load bearing surface on at least one of said ball portion and said cup portion of said prosthetic joint; and a diamond-like coating on the ceramic load bearing surface, said diamond-like coating comprising an amorphous and cross-linked carbon network and wherein said diamond-like coating includes inter-atomic bonds between said ceramic and said diamond like coating.
 2. The prosthesis of claim 1 wherein said ion implanted ceramic is on said ball portion of said prosthetic joint.
 3. The prosthesis of claim 1 wherein said ion implanted ceramic is on said cup portion of said prosthetic joint.
 4. The prosthesis of claim 1 wherein said ball and said cup portion each including load bearing surfaces defining a tensile stress, wherein at least one of said ball and said cup portions comprises said ion implanted ceramic having said compressive stress sufficient to counteract said tensile stress.
 5. The prosthesis of claim 1 wherein said ion-implanted ceramic is further characterized as having a maximum compressive stress in said surface due to said ion implantation wherein said ceramic with said maximum compressive stress is not amorphous.
 6. The prosthesis of claim 1, wherein the prosthetic joint comprises a knee joint, a finger joint, a toe joint, a shoulder joint, an arm joint, an elbow joint, a hip joint, an ankle joint, a neck joint, a spinal cord joint, and a combination thereof.
 7. The prosthesis of claim 1, wherein the ceramic is selected from a group consisting of Alumina (Al₂O₃), Zirconia, Chromium Oxide (Cr₂O₃), Silicon Oxide (SiO₂) and a combination thereof.
 8. The prosthesis of claim 1, wherein the ceramic treated with ion implantation comprises a ceramic treated at a concentration of about 1×10¹⁷ ions per cm² or less.
 9. The prosthesis of claim 1, wherein the ion implanted in said ceramic is selected from a group consisting of positive ions, nitrogen ions, calcium ions, hydrogen ions, boron ions, and a combination thereof.
 10. A prosthesis, comprising: a prosthetic joint comprising a ball portion and a cup portion said ball portion having an outer load bearing surface configured to engage with a load bearing surface within said cup potion; a ceramic treated with ion implantation, wherein said ion implanted ceramic is characterized as having a compressive stress in said surface due to said ion implantation wherein said ion-implanted ceramic with said compressive stress is not amorphous, wherein said ion implanted ceramic is said load bearing surface on at least one of said ball portion and said cup portion of said prosthetic joint.
 11. The prosthesis of claim 10 wherein said ion implanted ceramic is on said ball portion of said prosthetic joint.
 12. The prosthesis of claim 10 wherein said ion implanted ceramic is on said cup portion of said prosthetic joint.
 13. The prosthesis of claim 10 wherein said ball and said cup portion each including load bearing surfaces defining a tensile stress, wherein at least one of said ball and said cup portions comprises said ion implanted ceramic having said compressive stress sufficient to counteract said tensile stress.
 14. The prosthesis of claim 10 wherein said ion-implanted ceramic is further characterized as having a maximum compressive stress in said surface due to said ion implantation wherein said ceramic with said maximum compressive stress is not amorphous.
 15. The prosthesis of claim 10, wherein said prosthetic joint comprises a knee joint, a finger joint, a toe joint, a shoulder joint, an arm joint, an elbow joint, a hip joint, an ankle joint, a neck joint, a spinal cord joint, and a combination thereof.
 16. The prosthesis of claim 10, wherein the ceramic is selected from a group consisting of Alumina (Al₂O₃), Zirconia, Chromium Oxide (Cr₂O₃), Silicon Oxide (SiO₂) and a combination thereof.
 17. The prosthesis of claim 10, wherein the ceramic treated with ion implantation comprises a ceramic treated at a concentration of about 1×10¹⁷ ions per cm² or less.
 18. The prosthesis of claim 10, wherein said ion implanted in said ceramic is selected from a group consisting of positive ions, nitrogen ions, calcium ions, hydrogen ions, boron ions, and a combination thereof.
 19. The prosthesis of claim 10, further comprising a diamond-like coating on said ceramic.
 20. The prosthesis of claim 19 wherein said diamond-like coating further comprises an amorphous and cross-linked carbon network and wherein said diamond-like coating includes inter-atomic bonds between said ceramic and said diamond-like coating. 